I'm migrating a cell-based NSTableView to be view-based. With NSCell, to determine if a cell was highlighted (e.g., to draw the text in white instead of black), I looked at the NSCell highlighted property.
What's the NSView version of this? I can't find anything like this in the docs.
The easiest way to do this is to simply subclass NSTableCellView. All the documentation says that you can subclass either NSTableCellView or NSView, e.g., Table View Programming Guide for Mac:
Drag an NSTableCellView object (or a custom view) from the object library to the appropriate column in the table view. ... Typically, the view class is a subclass of NSTableCellView.
It doesn't say what this is, or why you'd want to use it. It looks like an NSView which has an NSTextField and an NSImageView, and that's it -- so if you're not making a view that has these, it's tempting to ignore this class and just subclass NSView.
Interestingly, though, if you have any NSTextFields in an NSTableCellView (even if you don't use the textField property for this!), they automatically use the correct light/dark coloring.
In particular, it seems that the backgroundStyle property of NSTableCellView is what causes the text value to actually change. The documentation says:
The default implementation automatically forwards calls to all subviews that implement setBackgroundStyle: or are an NSControl, which have NSCell classes that respond to setBackgroundStyle:.
NSTextField is an NSControl with an NSCell, of course, so it gets this called on it.
While it's not exactly clear in Apple's documentation (what does "this" refer to?), it seems that NSTableView calls -setBackgroundStyle: on any view that defines it. So if you don't want to subclass NSTableCellView, you can alternatively just add a property to your own NSView:
var backgroundStyle: NSBackgroundStyle
and have your drawing code use that.
Related
I just want to know what this QtObject elements does, its seems that is reactive, because in the tutorial that I followed, use it for update the color of a button, so, I want to know how I can use it, and how its works, and how I can use in other cases.
while your are working on QML file need to hide some properties from upper layer Item ( some thing's like private variable and methods).
best case for get a right way for incapsulation in QML is to using a internal item like QtObject .
in your code used a QtObject for block the external direct access to button color and bind the color to the button item state.
I assume you've read the docs? A QtObject is just the most basic type of of QML object. It doesn't do anything by itself. It's not visual. So it's just used for holding other properties.
In the example you provided, it's being used as a way to make pseudo-private variables. QML has no such thing as private variables, but if you put properties inside of an object, then they are not accessible to anything outside of this file (unless explicitly exposed). That's all it's being used for in your example. If you took the property dynamicColor and moved it outside of the QtObject, the code would still work exactly the same way. The only difference would be other QML files would be able to access (and therefore modify) dynamicColor.
I've to deal with a scientific application and thus have to use RTF at many place (think about displaying units with exponents mainly).
I've implemented a delegate to deal with tables and drop box and it works mostly fine. (implementation : http://pastebin.com/FuCbGqkY , header : http://pastebin.com/D6hxeWdF ).
However, I've been into a major issue : it looks like the "button" part of the QComboBox is not rendered with the delegate (it only applies to the drop down box). Is there any way to have the text in the combobox when it's not dropped displayed correctly ? If not, what do I have to do ? Subclass and overwrite paint method ? Looks like a lot of pain and basically it makes the delegate useless.
Any clue ?
Consider QComboBox::lineEdit() method. You can try to apply your changes to the QLineEdit directly if it's possible. Otherwise you can subclass QLineEdit and change its behaviour to what you want, and then insert it using QComboBox::setLineEdit. Maybe you will need to make the combo box editable in order to use this.
I have just changed some toolbars from Q3ToolBars (with QToolButtons explicitly added to them) into Q4 toolbars (with actions added to them straight away instead.)
The old tool buttons had a nice outline around them, but this is not displayed in the new version; the QActions in the Q4 toolbar just look like a line of icons. Is there a way to change the 'button' style in the new version (assuming these actions can be considered as such) and give them the outline? I've looked through the QToolBar reference, but the toolButtonStyle() function only appears to work with whether you want to display icon, text, etc.
...Or will I have to just make actual tool buttons and/or QPushButtons and use addWidget()?
The widget associated with a given action is accessible through QToolBar::widgetForAction (since Qt 4.2). So, you can pass your actions to this method, get the QWidgets returned by it, convert them to QToolBar, and handle them like you normally would (code not tested):
// ...
auto toolButton =
static_cast<QToolButton *>(
m_ui.toolbar->widgetForAction(m_ui.my_Action));
// Will make the toolButton always appear raised:
toolButton->setAutoRaise(false);
// ...
As far as I've been testing, some methods might not work (i.e., QWidget::hide), so do your own testing.
Yes, of course you can edit look of QToolButtons in two different ways:
You can set it style sheet using void QWidget::setStyleSheet(const QString &)
You can reimplement QToolButtons class with new paintEvent function where you will be able to exactly set how your button should looks like.
I want a widget like the properties window in Visual Studio or NetBeans. It basically has two columns: the name of the property on the left, and the value on the right. The value needs to be able to be restricted to certain types, like 'bool' or 'float' (with valid ranges), but should also support more complex types (perhaps requiring a popup dialog when clicked, and then it can just display a toString() version in the window. I'm sure I can add most of those features myself, but what's the best base widget to start with?
Oh... grouping of properties is good too (like a tree I guess). And property editing should invoke a callback (send a signal).
Qt designer has properties exactly like you want. They are most likely implemented with QTreeView. You can always look at the source code.
QTreeView or QTableView. Do all (ok, most) of the heavy lifting with a specialized model that handles all of your type restrictions and what-not. Check out delegates as well.
Here's a link led to github, it might be useful.
another userful link
I've got a QTableView for which I want to display the last column always in edit mode. (It's a QComboBox where the user should be able to always change the value.)
I think I've seen the solution in the Qt documentation, but I can't find it anymore. Is there a simple way of doing it?
I think I could archive this effect by using openPersistentEditor() for every cell, but I'm looking for a better way. (Like specifying it only one time for the whole column.)
One way to get the automatic editing behaviour is to call the view's setEditTriggers() function with the QAbstractItemView::AllEditTriggers value.
To display the contents of a given column in a certain way, take a look at QAbstractItemView::setItemDelegateForColumn(). This will let you specify a custom delegate just for those items that need it. However, it won't automatically create an editor widget for each of them (there could in principle be thousands of them), but you could use the delegate to render each item in a way that makes it look like an editor widget.
There are two possibilities:
Using setIndexWidget, but Trolltech writes:
This function should only be used to
display static content within the
visible area corresponding to an item
of data. If you want to display custom
dynamic content or implement a custom
editor widget, subclass QItemDelegate
instead.
(And it breaks the Model/View pattern…)
Or using a delegate's paint method. But here you have to implement everything like enabled/disabled elements yourself.
The QAbstractItemModel::flags virtual function is called to test if an item is editable (see Qt::ItemIsEditable). Take a look at Making the Model Editable in the Model/View Programming documentation.
I can't see an easy way to do this, but you might be able to manage by using a delegate. I honestly don't know exactly how it would work, but you should be able to get something working if you try hard enough. If you get a proper delegate, you should be able to set it on a whole view, one cell of a view, or just a column or row.